1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_PGTABLE_64_H
3 #define _ASM_X86_PGTABLE_64_H
4
5 #include <linux/const.h>
6 #include <asm/pgtable_64_types.h>
7
8 #ifndef __ASSEMBLER__
9
10 /*
11 * This file contains the functions and defines necessary to modify and use
12 * the x86-64 page table tree.
13 */
14 #include <asm/processor.h>
15 #include <linux/bitops.h>
16 #include <linux/threads.h>
17 #include <asm/fixmap.h>
18
19 extern p4d_t level4_kernel_pgt[512];
20 extern p4d_t level4_ident_pgt[512];
21 extern pud_t level3_kernel_pgt[512];
22 extern pmd_t level2_kernel_pgt[512];
23 extern pmd_t level2_fixmap_pgt[512];
24 extern pte_t level1_fixmap_pgt[512 * FIXMAP_PMD_NUM];
25 extern pgd_t init_top_pgt[];
26
27 #define swapper_pg_dir init_top_pgt
28
29 extern void paging_init(void);
sync_initial_page_table(void)30 static inline void sync_initial_page_table(void) { }
31
32 #define pte_ERROR(e) \
33 pr_err("%s:%d: bad pte %p(%016lx)\n", \
34 __FILE__, __LINE__, &(e), pte_val(e))
35 #define pmd_ERROR(e) \
36 pr_err("%s:%d: bad pmd %p(%016lx)\n", \
37 __FILE__, __LINE__, &(e), pmd_val(e))
38 #define pud_ERROR(e) \
39 pr_err("%s:%d: bad pud %p(%016lx)\n", \
40 __FILE__, __LINE__, &(e), pud_val(e))
41
42 #define p4d_ERROR(e) \
43 pr_err("%s:%d: bad p4d %p(%016lx)\n", \
44 __FILE__, __LINE__, &(e), p4d_val(e))
45
46 #define pgd_ERROR(e) \
47 pr_err("%s:%d: bad pgd %p(%016lx)\n", \
48 __FILE__, __LINE__, &(e), pgd_val(e))
49
50 struct mm_struct;
51
52 #define mm_p4d_folded mm_p4d_folded
mm_p4d_folded(struct mm_struct * mm)53 static inline bool mm_p4d_folded(struct mm_struct *mm)
54 {
55 return !pgtable_l5_enabled();
56 }
57
58 void set_pte_vaddr_p4d(p4d_t *p4d_page, unsigned long vaddr, pte_t new_pte);
59 void set_pte_vaddr_pud(pud_t *pud_page, unsigned long vaddr, pte_t new_pte);
60
native_set_pte(pte_t * ptep,pte_t pte)61 static inline void native_set_pte(pte_t *ptep, pte_t pte)
62 {
63 WRITE_ONCE(*ptep, pte);
64 }
65
native_pte_clear(struct mm_struct * mm,unsigned long addr,pte_t * ptep)66 static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr,
67 pte_t *ptep)
68 {
69 native_set_pte(ptep, native_make_pte(0));
70 }
71
native_set_pte_atomic(pte_t * ptep,pte_t pte)72 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
73 {
74 native_set_pte(ptep, pte);
75 }
76
native_set_pmd(pmd_t * pmdp,pmd_t pmd)77 static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
78 {
79 WRITE_ONCE(*pmdp, pmd);
80 }
81
native_pmd_clear(pmd_t * pmd)82 static inline void native_pmd_clear(pmd_t *pmd)
83 {
84 native_set_pmd(pmd, native_make_pmd(0));
85 }
86
native_ptep_get_and_clear(pte_t * xp)87 static inline pte_t native_ptep_get_and_clear(pte_t *xp)
88 {
89 #ifdef CONFIG_SMP
90 return native_make_pte(xchg(&xp->pte, 0));
91 #else
92 /* native_local_ptep_get_and_clear,
93 but duplicated because of cyclic dependency */
94 pte_t ret = *xp;
95 native_pte_clear(NULL, 0, xp);
96 return ret;
97 #endif
98 }
99
native_pmdp_get_and_clear(pmd_t * xp)100 static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
101 {
102 #ifdef CONFIG_SMP
103 return native_make_pmd(xchg(&xp->pmd, 0));
104 #else
105 /* native_local_pmdp_get_and_clear,
106 but duplicated because of cyclic dependency */
107 pmd_t ret = *xp;
108 native_pmd_clear(xp);
109 return ret;
110 #endif
111 }
112
native_set_pud(pud_t * pudp,pud_t pud)113 static inline void native_set_pud(pud_t *pudp, pud_t pud)
114 {
115 WRITE_ONCE(*pudp, pud);
116 }
117
native_pud_clear(pud_t * pud)118 static inline void native_pud_clear(pud_t *pud)
119 {
120 native_set_pud(pud, native_make_pud(0));
121 }
122
native_pudp_get_and_clear(pud_t * xp)123 static inline pud_t native_pudp_get_and_clear(pud_t *xp)
124 {
125 #ifdef CONFIG_SMP
126 return native_make_pud(xchg(&xp->pud, 0));
127 #else
128 /* native_local_pudp_get_and_clear,
129 * but duplicated because of cyclic dependency
130 */
131 pud_t ret = *xp;
132
133 native_pud_clear(xp);
134 return ret;
135 #endif
136 }
137
native_set_p4d(p4d_t * p4dp,p4d_t p4d)138 static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d)
139 {
140 pgd_t pgd;
141
142 if (pgtable_l5_enabled() ||
143 !IS_ENABLED(CONFIG_MITIGATION_PAGE_TABLE_ISOLATION)) {
144 WRITE_ONCE(*p4dp, p4d);
145 return;
146 }
147
148 pgd = native_make_pgd(native_p4d_val(p4d));
149 pgd = pti_set_user_pgtbl((pgd_t *)p4dp, pgd);
150 WRITE_ONCE(*p4dp, native_make_p4d(native_pgd_val(pgd)));
151 }
152
native_p4d_clear(p4d_t * p4d)153 static inline void native_p4d_clear(p4d_t *p4d)
154 {
155 native_set_p4d(p4d, native_make_p4d(0));
156 }
157
native_set_pgd(pgd_t * pgdp,pgd_t pgd)158 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
159 {
160 WRITE_ONCE(*pgdp, pti_set_user_pgtbl(pgdp, pgd));
161 }
162
native_pgd_clear(pgd_t * pgd)163 static inline void native_pgd_clear(pgd_t *pgd)
164 {
165 native_set_pgd(pgd, native_make_pgd(0));
166 }
167
168 /*
169 * Conversion functions: convert a page and protection to a page entry,
170 * and a page entry and page directory to the page they refer to.
171 */
172
173 /* PGD - Level 4 access */
174
175 /* PUD - Level 3 access */
176
177 /* PMD - Level 2 access */
178
179 /* PTE - Level 1 access */
180
181 /*
182 * Encode and de-code a swap entry
183 *
184 * | ... | 11| 10| 9|8|7|6|5| 4| 3|2| 1|0| <- bit number
185 * | ... |SW3|SW2|SW1|G|L|D|A|CD|WT|U| W|P| <- bit names
186 * | TYPE (59-63) | ~OFFSET (9-58) |0|0|X|X| X| E|F|SD|0| <- swp entry
187 *
188 * G (8) is aliased and used as a PROT_NONE indicator for
189 * !present ptes. We need to start storing swap entries above
190 * there. We also need to avoid using A and D because of an
191 * erratum where they can be incorrectly set by hardware on
192 * non-present PTEs.
193 *
194 * SD Bits 1-4 are not used in non-present format and available for
195 * special use described below:
196 *
197 * SD (1) in swp entry is used to store soft dirty bit, which helps us
198 * remember soft dirty over page migration
199 *
200 * F (2) in swp entry is used to record when a pagetable is
201 * writeprotected by userfaultfd WP support.
202 *
203 * E (3) in swp entry is used to remember PG_anon_exclusive.
204 *
205 * Bit 7 in swp entry should be 0 because pmd_present checks not only P,
206 * but also L and G.
207 *
208 * The offset is inverted by a binary not operation to make the high
209 * physical bits set.
210 */
211 #define SWP_TYPE_BITS 5
212
213 #define SWP_OFFSET_FIRST_BIT (_PAGE_BIT_PROTNONE + 1)
214
215 /* We always extract/encode the offset by shifting it all the way up, and then down again */
216 #define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS)
217
218 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS)
219
220 /* Extract the high bits for type */
221 #define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS))
222
223 /* Shift up (to get rid of type), then down to get value */
224 #define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT)
225
226 /*
227 * Shift the offset up "too far" by TYPE bits, then down again
228 * The offset is inverted by a binary not operation to make the high
229 * physical bits set.
230 */
231 #define __swp_entry(type, offset) ((swp_entry_t) { \
232 (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \
233 | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) })
234
235 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) })
236 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val((pmd)) })
237 #define __swp_entry_to_pte(x) (__pte((x).val))
238 #define __swp_entry_to_pmd(x) (__pmd((x).val))
239
240 extern void cleanup_highmap(void);
241
242 #define HAVE_ARCH_UNMAPPED_AREA
243 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
244
245 #define PAGE_AGP PAGE_KERNEL_NOCACHE
246 #define HAVE_PAGE_AGP 1
247
248 /* fs/proc/kcore.c */
249 #define kc_vaddr_to_offset(v) ((v) & __VIRTUAL_MASK)
250 #define kc_offset_to_vaddr(o) ((o) | ~__VIRTUAL_MASK)
251
252 #define __HAVE_ARCH_PTE_SAME
253
254 #define vmemmap ((struct page *)VMEMMAP_START)
255
256 extern void init_extra_mapping_uc(unsigned long phys, unsigned long size);
257 extern void init_extra_mapping_wb(unsigned long phys, unsigned long size);
258
259 #define gup_fast_permitted gup_fast_permitted
gup_fast_permitted(unsigned long start,unsigned long end)260 static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
261 {
262 if (end >> __VIRTUAL_MASK_SHIFT)
263 return false;
264 return true;
265 }
266
267 #include <asm/pgtable-invert.h>
268
269 #else /* __ASSEMBLER__ */
270
271 #define l4_index(x) (((x) >> 39) & 511)
272 #define pud_index(x) (((x) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
273
274 L4_PAGE_OFFSET = l4_index(__PAGE_OFFSET_BASE_L4)
275 L4_START_KERNEL = l4_index(__START_KERNEL_map)
276
277 L3_START_KERNEL = pud_index(__START_KERNEL_map)
278
279 #define SYM_DATA_START_PAGE_ALIGNED(name) \
280 SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE)
281
282 /* Automate the creation of 1 to 1 mapping pmd entries */
283 #define PMDS(START, PERM, COUNT) \
284 i = 0 ; \
285 .rept (COUNT) ; \
286 .quad (START) + (i << PMD_SHIFT) + (PERM) ; \
287 i = i + 1 ; \
288 .endr
289
290 #endif /* __ASSEMBLER__ */
291 #endif /* _ASM_X86_PGTABLE_64_H */
292